CN115041165A

CN115041165A - Biochar-loaded zero-valent copper and preparation and application method thereof

Info

Publication number: CN115041165A
Application number: CN202210661705.2A
Authority: CN
Inventors: 赵江; 陈天吟
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-06-11
Filing date: 2022-06-11
Publication date: 2022-09-13

Abstract

The invention relates to the technical field of water treatment, in particular to biochar-loaded zero-valent copper and a preparation and application method thereof, and Enrofloxacin (ENR) is taken as a typical novel organic pollutant to carry out experiments. The preparation method of the biochar loaded zero-valent copper comprises the following steps: weighing straws and copper chloride dihydrate, stirring, fully and uniformly mixing, drying, putting a proper amount of dried mixture into a crucible, putting the crucible into a tubular furnace for calcining, cooling, taking out, grinding and sieving to obtain the biochar loaded zero-valent copper. The method for repairing ENR pollution in water by using the peroxymonosulfate-biochar loaded zero-valent copper adds the peroxymonosulfate and the biochar loaded zero-valent copper into ENR polluted surface water and underground water by controlling certain reaction conditions, and the removal rate of ENR in water under acidic, neutral and alkaline conditions can reach 100 percent.

Description

Biochar-loaded zero-valent copper and preparation and application method thereof

Technical Field

The invention relates to the technical field of water treatment, in particular to biochar-loaded zero-valent copper and a preparation and application method thereof.

Background

With the rapid development of industry and the mass production of various chemicals, new pollutants (CECs), such as Pharmaceuticals and Personal Care Products (PPCPs), Endocrine Disruptors (EDCs), and perfluorinated compounds (PFCs), have been the focus of research in the field of water treatment because they are difficult to completely remove by conventional water and wastewater treatment processes. Among them, antibiotics, which are the most common type of PPCPs, are widely used as bactericides in human and animal health care, and continue to exist stably in nature after being discharged, and may pose environmental and public health risks even at trace levels. Enrofloxacin (ENR) is an artificially synthesized antibiotic, and belongs to the third-generation fluoroquinolone medicines. It has broad-spectrum and strong bactericidal action, and is widely applied to animal medicine. ENR also has the characteristics of difficult biodegradation and long durability (the half-life period reaches 3-9 years), so that ENR is easy to enter water environment through poultry excrement and feed, including poultry breeding wastewater, effluent of a sewage treatment plant, surface water, underground water, tap water and the like, and has great threat to human health and aquatic ecosystem.

Currently, advanced oxidation technology is the most effective method for treating refractory pollutants. Compared with the advanced oxidation technology based on hydroxyl free radical (. OH), the advanced oxidation technology based on the sulfuric acid free radical (SO 4-), is regarded as a technology with more practical application potential due to the characteristics of fast reaction rate, strong oxidation capacity, wide pH application range, long half-life time (30-40 mus) of the free radical and good adaptability in different water bodies. Peronosulfate (PMS) is a common persulfate oxidizer, and activation of the PMS is critical to the application of this technology. Conventional activation methods include energy activation (e.g., heat, ultraviolet light, and microwave), transition metal ion or transition metal oxide activation, carbon material activation (e.g., carbon nanotubes, graphene, and biochar), and the like. The energy activation requires the construction of related equipment, the process cost is relatively high, and meanwhile, the continuous input of energy is required in the treatment process, which easily results in a large amount of energy loss. Carbon-based catalysts generally exhibit good adsorption capacity, and adsorption merely transfers the contaminants, without degrading the target contaminants into small molecules, which still are potentially harmful to the environment. Although the activation of the transition metal ions or the transition metal oxides has wider use conditions and higher activation efficiency, the activation is easily limited by the agglomeration of the metal ions, so that the transition metal ions or the transition metal oxides are unevenly distributed in surface water and underground water, and the overall treatment effect is difficult to achieve the ideal condition. Meanwhile, the leaching of metal ions can also cause the problem of secondary pollution of water.

Compared with transition metal ions and an oxidant, the zero-valent transition metal has less metal ions leached in the process of activating the peroxymonosulfate, and the zero-valent transition metal and corrosion products thereof can gradually activate the peroxymonosulfate, thereby forming a more efficient and durable pollutant degradation effect in surface water and underground water environment. The activation effect of the zero-valent copper is in the first place of the neutral position of the zero-valent transition metal, and the copper also has the characteristics of low toxicity, easy acquisition and low cost, and is suitable for practical application and industrial production.

Therefore, the biochar-loaded zero-valent copper which overcomes the defect of metal agglomeration is developed, and the biochar-loaded zero-valent copper material which is environment-friendly, stable and efficient and is applied to novel organic matter pollution remediation engineering in surface water and underground water is prepared by using the biochar as a carrier, and the preparation method and the application of the biochar-loaded zero-valent copper have market prospects and remediation needs.

The above information disclosed in this background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

The invention provides a preparation and application method of biochar-loaded zero-valent copper, and a method for repairing novel organic pollution in surface water and underground water by using the cooperation of peroxymonosulfate and biochar-loaded zero-valent copper, overcomes the defects of high cost and high energy consumption of an energy activated peroxymonosulfate system and the problem of secondary pollution caused by high leaching rate of metal ions in a metal ion activated peroxymonosulfate system, solves the problem of easy agglomeration of zero-valent copper in a water body, has the characteristics of high efficiency and durability in treatment, simple preparation process, convenience in process operation and the like, and can be widely applied to repairing novel organic pollution difficult to degrade in the water body.

In order to achieve the above purpose, the invention provides the following technical scheme: a preparation method of biochar loaded zero-valent copper comprises the following steps:

s1, weighing copper chloride dihydrate and straws in corresponding mass proportion, placing the copper chloride dihydrate and the straws in a beaker, stirring the copper chloride dihydrate and the straws in the beaker by using a rotating magnetic field of a magnetic stirrer at room temperature, and stirring for 24 hours at a rotating speed of 400rpm to fully mix copper ions and the straws.

S2, drying the fully and uniformly mixed mixture at 80 ℃ to constant weight.

S3, taking a proper amount of dried mixture into a crucible, and putting the crucible into a tube furnace to be filled with nitrogen so as to remove oxygen in the furnace chamber. And introducing nitrogen for 10min, starting a tubular furnace, raising the temperature by program, heating to 900 ℃ at the speed of 5 ℃/min, keeping the temperature for 2h, closing the tubular furnace, taking out after cooling, grinding by using a mortar, and sieving by using a 200-mesh sieve to obtain the biochar-loaded zero-valent copper.

Preferably, in step S1, the mass ratio of the copper chloride dihydrate to the straw is 1: 1.5.

As a general technical concept, the invention also provides application of the biochar-loaded zero-valent copper in removing refractory organic pollutants in a water body.

Firstly, adding peroxymonosulfate into wastewater, then regulating the pH value of wastewater containing novel organic pollutants (ENR) by using sulfuric acid and sodium hydroxide, then adding biochar loaded zero-valent copper into the wastewater, and then placing the wastewater on a constant-temperature magnetic stirrer for degradation reaction. The removal rate of pollutants (ENR) in the treated wastewater can reach 100 percent at most under acidic, neutral and alkaline conditions.

Preferably, the pH value of the wastewater is adjusted within the range of 2-11.

Preferably, the concentration of the contaminant (ENR) in the wastewater is 10 mg/L.

Preferably, the peroxymonosulfate concentration is 72 times the contaminant (ENR) concentration.

Preferably, the average grain diameter of the zero-valent copper loaded on the biochar is 200 meshes, and the adding amount is 5-40 times of the concentration of the pollutants (ENR).

Preferably, the temperature of the constant-temperature magnetic stirrer is normal temperature, the rotating speed is 900rpm, and the stirring time is 0.5-12 hours.

In the invention, the peroxymonosulfate mainly serves to provide active oxygen species, the peroxymonosulfate is relatively stable in a normal temperature environment, and the active oxygen species generated after activation has a very strong oxidation effect, can quickly oxidize and mineralize refractory organic pollutants, and can remove the refractory organic pollutants.

In the invention, the zero-valent copper mainly has the function of activating the peroxymonosulfate to generate active oxygen species so as to oxidize and degrade organic pollutants, and the zero-valent copper can be gradually corroded into monovalent copper ions and divalent copper ions in the process, and the copper ions can further activate the peroxymonosulfate. Meanwhile, the surface property of the biochar can be changed by the load of the zero-valent copper, and the adsorption of the biochar-loaded copper on the peroxymonosulfate is increased, so that the activation rate is improved.

In the invention, the biochar has the main functions of simultaneously adsorbing organic pollutants and peroxymonosulfate and improving the degradation rate of the pollutants. In addition, the biochar can effectively prevent zero-valent copper from agglomerating, and the contact area of the reaction is increased.

In the technical scheme, the invention provides the following technical effects and advantages:

1. according to the method, biochar loaded zero-valent copper is used for activating the peroxymonosulfate to generate a plurality of active oxygen species such as sulfate radical free radicals, hydroxyl free radicals, singlet oxygen, superoxide anion free radicals and the like to synergistically oxidize and degrade enrofloxacin, so that the method has the advantages of low cost, difficulty in catalyst agglomeration, strong material stability, high and lasting pollution removal efficiency, wide application range, simple process flow, convenience in operation and the like, and can be applied to in-situ remediation or pumping treatment of novel organic pollutant ENR pollution;

2. the method has the advantages of low material cost, good stability, strong water body adaptability, high removal efficiency, simple process flow and convenient operation, effectively utilizes the synergistic effect of the peroxymonosulfate and the biochar loaded zero-valent copper and the adsorption and agglomeration prevention effects of the biochar, and can realize the efficient and lasting removal of new organic pollutants in the water body.

Drawings

For a clearer explanation of the embodiments of the present application or technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to the drawings.

FIG. 1 is a comparison graph of ENR removal effects of biochar-loaded zero-valent copper, biochar, peroxymonosulfate-biochar and peroxymonosulfate-biochar-loaded zero-valent copper of the present invention;

FIG. 2 is a graph comparing the effect of removing contaminants (ENR) by peroxymonosulfate-biochar loaded zero valent copper in an acidic, neutral, or alkaline aqueous environment in accordance with the present invention;

FIG. 3 is a graph comparing the effect of persulfate-biochar-loaded zero-valent copper on contaminant removal (ENR) for different copper chloride dihydrate and straw mass ratios according to the present invention;

FIG. 4 is a graph comparing the effect of different dosing ratios of peroxymonosulfate and biochar loaded zero valent copper on contaminant removal (ENR) in accordance with the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The described features, structures, or characteristics may be combined in any suitable manner in one or more exemplary embodiments. In the following description, numerous specific details are provided to give a thorough understanding of example embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the subject matter of the present disclosure can be practiced without one or more of the specific details, or with other methods, components, steps, and so forth. In other instances, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure;

in order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.

Example 1:

(1) weighing the components in a mass ratio of 1:1, placing the copper chloride dihydrate and the straws in a beaker, and stirring the copper chloride dihydrate and the straws in the beaker for 24 hours at the rotating speed of 400rpm by using a magnetic stirrer at room temperature.

(2) The well mixed mixture is dried at 80 ℃ to constant weight.

(3) Taking a proper amount of dried mixture into a crucible, putting the crucible into a tubular furnace, and introducing nitrogen to remove oxygen in the furnace chamber. And introducing nitrogen for 10min, starting a tubular furnace, raising the temperature by a program, heating to 900 ℃ at the speed of 5 ℃/min, keeping the temperature for 2h for carbonization, closing the tubular furnace, taking out after cooling, grinding by using a mortar, and sieving by using a 200-mesh sieve to obtain the biochar loaded zero-valent copper.

Example 2:

a preparation method of biochar loaded zero-valent copper comprises the following steps of (1) except for the mass ratio of copper chloride dihydrate to straw: except for 2, the other operation steps are the same as in example 1.

Example 3:

a preparation method of biochar loaded zero-valent copper comprises the following steps of (1) except for the mass ratio of copper chloride dihydrate to straw: except for 5, the other operation steps are the same as in example 1.

Example 4:

the application of biochar-loaded zero-valent copper is specifically to remove pollutants (ENR) in a water body by using the cooperation of peroxymonosulfate-biochar-loaded zero-valent copper, and comprises the following steps:

preparing 100mL of ENR solution containing 10mg/L, adding 200mg/L of peroxymonosulfate into 100mL of ENR solution containing 10mg/L, loading zero-valent copper on 300mg/L of charcoal, adjusting the initial pH value to 3, reacting on a constant-temperature magnetic stirrer at 25 ℃ at 900r/min, and enabling the removal rate of pollutants (ENR) in 100mL of ENR solution containing 10mg/L to reach 100% at 10 min.

Example 5:

an application of biochar-loaded zero-valent copper, in particular to biochar-loaded zero-valent copper prepared by straw and copper chloride dihydrate with different mass ratios and added with peroxymonosulfate to remove pollutants (ENR) in a water body, which comprises the following steps:

three kinds of charcoal-supported zero-valent copper were obtained according to the preparation methods in examples 1, 2, and 3.

Preparing 100mL of ENR solution containing 10mg/L, adding 100mg/L of peroxymonosulfate into 100mL of ENR solution containing 10mg/L, loading 200mg/L of biochar with zero-valent copper, adjusting the initial pH to 9, and reacting on a constant-temperature magnetic stirrer at 25 ℃ at 900 r/min. The result is shown in figure 3, the copper chloride dihydrate and the straw have good degradation effect on pollutants (ENR) within the mass ratio of 1-1: 5, and the degradation efficiency can reach 100% within 60 min.

Example 6:

the application of biochar loaded zero-valent copper is specifically to remove pollutants (ENR) in a water body by using biochar loaded zero-valent copper and peroxymonosulfate with different mass ratios, and comprises the following steps:

preparing 100mL of ENR solution containing 10mg/L, adding 200mg/L of peroxymonosulfate into 100mL of ENR solution containing 10mg/L, then respectively adding 50mg/L, 100mg/L, 200mg/L, 300mg/L and 400mg/L of biochar loaded zero-valent copper, adjusting the initial pH to 3, and reacting on a constant-temperature magnetic stirrer at 25 ℃ at 900 r/min. As a result, as shown in FIG. 4, the removal efficiencies of ENR were 99.26%, 100%, 100%, and 100% in 60min, respectively, at different mass ratios.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the invention.

The points to be finally explained are: first, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may be a mechanical connection or an electrical connection, or a communication between two elements, and may be a direct connection, and "upper," "lower," "left," and "right" are only used to indicate a relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may be changed;

secondly, the method comprises the following steps: in the drawings of the disclosed embodiments of the invention, only the structures related to the disclosed embodiments are referred to, other structures can refer to common designs, and the same embodiment and different embodiments of the invention can be combined with each other without conflict;

the previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention.

Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein;

and finally: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.

Claims

1. The preparation method of the biochar loaded zero-valent copper is characterized by comprising the following steps:

S2, drying the fully and uniformly mixed mixture at 80 ℃ to constant weight.

S3, taking a proper amount of dried mixture into a crucible, and putting the crucible into a tubular furnace to introduce nitrogen so as to remove oxygen in the furnace chamber. And introducing nitrogen for 10min, starting a tubular furnace, raising the temperature by a program, heating to 900 ℃ at the speed of 5 ℃/min, keeping the temperature for 2h for carbonization, closing the tubular furnace, taking out after cooling, grinding by using a mortar, and sieving by using a 200-mesh sieve to obtain the biochar loaded zero-valent copper.

2. The method for preparing the biochar-loaded zero-valent copper according to claim 1, which is characterized in that: in step S1, the mass ratio of the copper chloride dihydrate to the straw is 1: 1.5.

3. Use of the biochar-loaded zero-valent copper of claim 2 in the removal of organic contaminants in a body of water.

4. The use of claim 3, in a method for remediating new organic pollution in surface water and groundwater by using zero-valent copper loaded with peroxymonosulfate-biochar, which comprises the following steps: firstly adding peroxymonosulfate into wastewater, then regulating the pH value of wastewater containing novel organic pollutants (ENR) by using sulfuric acid and sodium hydroxide, then adding biochar loaded zero-valent copper into the wastewater, and then placing the wastewater on a constant-temperature magnetic stirrer for degradation reaction.

5. The method for remediating novel organic pollution in surface water and underground water by using the peroxymonosulfate-biochar loaded zero-valent copper as claimed in claim 4, wherein the method comprises the following steps: the pH value of the wastewater is adjusted within the range of 2-11.

6. The method for remediating novel organic pollution in surface water and underground water by using the peroxymonosulfate-biochar loaded zero-valent copper as claimed in claim 4, wherein the method comprises the following steps: the concentration of contaminants (ENR) in the wastewater was 10 mg/L.

7. The method for remediating novel organic pollution in surface water and underground water by using the peroxymonosulfate-biochar loaded zero-valent copper as claimed in claim 4, wherein the method comprises the following steps: the peroxymonosulfate concentration is 72 times the contaminant (ENR) concentration.

8. The method for remediating novel organic pollution in surface water and underground water by using the peroxymonosulfate-biochar loaded zero-valent copper as claimed in claim 4, wherein the method comprises the following steps: the average grain diameter of the zero-valent copper loaded on the biochar is 200 meshes, and the adding amount of the zero-valent copper loaded on the biochar is 5-40 times of the concentration of a pollutant (ENR).

9. The method for remediating novel organic pollution in surface water and underground water by using the peroxymonosulfate-biochar loaded zero-valent copper as claimed in claim 4, wherein the method comprises the following steps: the temperature of the constant-temperature magnetic stirrer is normal temperature, the rotating speed is 900rpm, and the stirring time is 0.5-12 hours.